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Study on the clogging mechanism of punching screen in sand control by the punching structure parameters

Petroleum Science 2024年第1期21卷 609-620页

作者： fu-Cheng Deng fu-Lin Gui Bai-Tao Fan Lei Wen Sheng-Hong Chen Ning Gong Yun-Chen Xiao zhi-Hui Xu yangtze University Jingzhou434023HubeiChina CNOOC Research Institute Ltd. Beijing100028China CNOOC Ener Tech-Drilling&Production Co. Tianjin300457China Tianjin Branch of CNOOC Ltd. Tianjin300459China

As an independent sand control unit or a common protective shell of a high-quality screen,the punching screen is the outermost sand retaining unit of the sand control pipe which is used in geothermal well or oil and gas ***,most screens only consider the influence of the internal sand retaining medium parameters in the sand control performance design while ignoring the influence of the plugging of the punching screen on the overall sand retaining performance of the *** explore the clogging mechanism of the punching screen,this paper established the clogging mechanism calculation model of a single punching screen sand control unit by using the computational fluid mechanics-discrete element method(CFD-DEM)combined *** to the combined motion of particles and fluids,the influence of the internal flow state on particle motion and accumulation was *** results showed that(1)the clogging process of the punching sand control unit is divided into three stages:initial clogging,aggravation of clogging and stability of *** the initial stage of blockage,coarse particles form a loose bridge structure,and blockage often occurs preferentially at the streamline gathering place below chamfering inside the sand control *** the stage of blockage intensification,the particle mass develops into a relatively complete sand bridge,which develops from both ends of the opening to the center of the *** the stable plugging stage,the sand deposits show a“fan shape”and form a“V-shaped”gully inside the punching slot element.(2)Under a certain reservoir particle-size distribution,The slit length and opening height have a large influence on the permeability and blockage rate,while the slit width size has little influence on the permeability and blockage *** microscopic clogging mechanism and its law of the punching screen prevention unit are proposed in this study,which has some field guidance significance for the design of punching screen

关键词： Punching screen Plugging CFD-DEM Size parameter Sand control

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Recent Advances in Cobalt-Catalyzed Regio-or Stereoselective Hydrofunctionalization of Alkenes and Alkynes

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CCS Chemistry 2024年第5期6卷 1130-1156页

作者： yan Li Xi Lu Yao fu Hefei National Research Center for Physical Sciences at the Microscale CAS Key Laboratory of Urban Pollutant ConversionAnhui Province Key Laboratory of Biomass Clean EnergyUniversity of Science and Technology of ChinaHefei 230026 Key Laboratory of Precision and Intelligent Chemistry Department of Applied ChemistrySchool of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefei 230026

Hydrofunctionalization of alkenes and alkynes is increasingly important in preparing and modifying carbon-centered organic molecules such as pharmaceuticals,agrochemicals,andmaterial *** development of transition-metal-catalysts has revolutionized the hydrofunctionalization of unsaturated hydrocarbons,greatly improving the synthetic efficiency and selectivity of these *** recent years,notable progress has been achieved in low-cost metal-catalyzed alkene and alkyne hydrofunctionalization reactions following the utilization of traditional precious metal catalysts,including palladium,platinum,and ***-abundant cobalt catalysts,which are low in toxicity and exhibit unique reactivity and selectivity,are widely implemented in academic and industrial *** this review,we highlight recent examples of cobalt-catalyzed hydrofunctionalization of alkenes and alkynes to provide an overview of hydrofunctionalization methods,particularly hydroalkylation *** reactions greatly expand the scope and utility of cobalt-catalyzed couplings of carbon—carbon *** also highlight the mechanistic considerations and selective determinants *** hope our discussion will be informative for future developments in cobalt catalysis and hydrofunctionalization reactions.

关键词： hydrofunctionalization cobalt-catalysis alkene alkyne regioselectivity stereoselectivity

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Machine learning for fault diagnosis of high-speed train traction systems: A review

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Frontiers of Engineering Management 2024年第1期11卷 62-78页

作者： Huan WANG yan-fu LI Jianliang REN Department of Industrial Engineering Tsinghua UniversityBeijing 100084China zhibo Lucchini Railway Equipment Co. Ltd.Taiyuan 030032China

High-speed trains(HSTs)have the advantages of comfort,efficiency,and convenience and have gradually become the mainstream means of *** the operating scale of HSTs continues to increase,ensuring their safety and reliability has become more *** the core component of HST,the reliability of the traction system has a substantially influence on the *** the long-term operation of HSTs,the core components of the traction system will inevitably experience different degrees of performance degradation and cause various failures,thus threatening the running safety of the ***,performing fault monitoring and diagnosis on the traction system of the HST is *** recent years,machine learning has been widely used in various pattern recognition tasks and has demonstrated an excellent performance in traction system fault *** learning has made considerably advancements in traction system fault diagnosis;however,a comprehensive systematic review is still lacking in this *** paper primarily aims to review the research and application of machine learning in the field of traction system fault diagnosis and assumes the future development ***,the structure and function of the HST traction system are briefly ***,the research and application of machine learning in traction system fault diagnosis are comprehensively and systematically ***,the challenges for accurate fault diagnosis under actual operating conditions are revealed,and the future research trends of machine learning in traction systems are discussed.

关键词： high-speed train traction systems machine learning fault diagnosis

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A Video Captioning Method by Semantic Topic-Guided Generation

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Computers, Materials & Continua 2024年第1期78卷 1071-1093页

作者： Ou Ye Xinli Wei Zhenhua Yu yan fu Ying yang College of Computer Science and Technology Xi’an University of Science and TechnologyXi’an710054China

In the video captioning methods based on an encoder-decoder,limited visual features are extracted by an encoder,and a natural sentence of the video content is generated using a ***,this kind ofmethod is dependent on a single video input source and few visual labels,and there is a problem with semantic alignment between video contents and generated natural sentences,which are not suitable for accurately comprehending and describing the video *** address this issue,this paper proposes a video captioning method by semantic topic-guided ***,a 3D convolutional neural network is utilized to extract the spatiotemporal features of videos during the ***,the semantic topics of video data are extracted using the visual labels retrieved from similar video *** the decoding,a decoder is constructed by combining a novel Enhance-TopK sampling algorithm with a Generative Pre-trained Transformer-2 deep neural network,which decreases the influence of“deviation”in the semantic mapping process between videos and texts by jointly decoding a baseline and semantic topics of video *** this process,the designed Enhance-TopK sampling algorithm can alleviate a long-tail problem by dynamically adjusting the probability distribution of the predicted ***,the experiments are conducted on two publicly used Microsoft Research Video Description andMicrosoft Research-Video to Text *** experimental results demonstrate that the proposed method outperforms several state-of-art ***,the performance indicators Bilingual Evaluation Understudy,Metric for Evaluation of Translation with Explicit Ordering,Recall Oriented Understudy for Gisting Evaluation-longest common subsequence,and Consensus-based Image Description Evaluation of the proposed method are improved by 1.2%,0.1%,0.3%,and 2.4% on the Microsoft Research Video Description dataset,and 0.1%,1.0%,0.1%,and 2.8% on the Microsoft Research-Video to Text dataset

关键词： Video captioning encoder-decoder semantic topic jointly decoding Enhance-TopK sampling

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Safety and efficacy of a programmed cell death 1 inhibitor combined with oxaliplatin plus S-1 in patients with Borrmann large type III and IV gastric cancers

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1281-1295页

作者： Zhe-Han Bao Can Hu yan-Qiang Zhang Peng-Cheng Yu Yi Wang zhi-Yuan Xu Huan-Ying fu Xiang-Dong Cheng Department of Interventional Radiology Zhejiang Cancer HospitalHangzhou 310004Zhejiang ProvinceChina Department of Gastric Surgery Zhejiang Cancer HospitalHangzhou 310022Zhejiang ProvinceChina Department of Colonic Surgery Jinhua Central HospitalJinhua 321000Zhejiang ProvinceChina Department of Breast Surgery Lin’an People’s HospitalHangzhou 311300Zhejiang ProvinceChina

BACKGROUND Gastric cancer(GC)is the fifth most common and the fourth most lethal malignant tumour in the *** patients are already in the advanced stage when they are diagnosed,which also leads to poor overall *** effect of posto-perative adjuvant chemotherapy for advanced GC is unsatisfactory with a high rate of distant metastasis and local *** To investigate the safety and efficacy of a programmed cell death 1(PD-1)inhibitor combined with oxaliplatin and S-1(SOX)in the treatment of Borrmann large type III and IV *** A retrospective analysis(IRB-2022-371)was performed on 89 patients with Borrmann large type III and IV GCs who received neoadjuvant therapy(NAT)from January 2020 to December *** to the different neoadjuvant treatment regimens,the patients were divided into the SOX group(61 patients)and the PD-1+SOX(P-SOX)group(28 patients).RESULTS The pathological response(tumor regression grade 0/1)in the P-SOX group was significantly higher than that in the SOX group(42.86%vs 18.03%,P=0.013).The incidence of ypN0 in the P-SOX group was higher than that in the SOX group(39.29%vs 19.67%,P=0.05).The use of PD-1 inhibitors was an independent factor affecting tumor regression ***,the use of PD-1 did not increase postoperative complications or the adverse effects of *** A PD-1 inhibitor combined with SOX could significantly improve the rate of tumour regression during NAT for patients with Borrmann large type III and IV GCs.

关键词： Neoadjuvant therapy Immunotherapy Gastric cancer Borrmann type Tumor regression grade

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The Effect of Blending Ratio on the Structure and Properties of the PPR/PS In situ Fiber Reinforced System Prepared by Multi-Flow Vibration Injection Molding

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Chinese Journal of Polymer Science 2024年第6期42卷 851-863页

作者： yan-Jiang Li Meng-Long Hu Jun-Wen Zhang Qiang fu Jie Zhang College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu610065China

To enhance the mechanical properties of polypropylene random copolymer(PPR),polystyrene(PS)with four different contents were added to the PPR matrix through melt ***,using the Multi-Flow Vibration Injection Molding(MFVIM)technology,PPR/PS in situ microfiber composites(MFC)with different blending ratios were *** results indicated that blending ratio had a great impact on the phase morphology and crystal structure of MFVIM samples,which was different from those of conventional injection molding(CIM)*** ultrafine fibers could be formed under the shear field and could absorb the PPR molecular chains to form hybrid shish-kebab ***,the PPR matrix could also form shish-kebab structures under the effect of strong *** the PS content reached 20%,under the combined action of PS in situ microfibers and highly oriented crystal structure,the tensile strength and Young’s modulus of the sample were obviously improved and the impact strength remained at a relatively high *** a strong and tough balanced PPR based material was *** results provide valuable insights for expanding the industrial and daily-life applications of PPR and show promising development prospects.

关键词： PPR MFVIM In situ microfibers Shearfield Hybrid shish-kebab structures

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Naturally Crosslinked Biocompatible Carbonaceous Liquid Metal Aqueous Ink Printing Wearable Electronics for Multi-Sensing and Energy Harvesting

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Nano-Micro Letters 2024年第8期16卷 148-168页

作者： King yan Chung Bingang Xu Di Tan Qingjun yang Zihua Li Hong fu Nanotechnology Center School of Fashion and TextilesThe Hong Kong Polytechnic UniversityHong Kong 999077People’s Republic of China Department of Mathematics and Information Technology The Education University of Hong KongHong KongPeople’s Republic of China

Achieving flexible electronics with comfort and durability comparable to traditional textiles is one of the ultimate pursuits of smart *** printing is desirable for e-textile development using a simple and inexpensive ***,fabricating high-performance atop textiles with good dispersity,stability,biocompatibility,and wearability for high-resolution,large-scale manufacturing,and practical applications has remained ***,waterbased multi-walled carbon nanotubes(MWCNTs)-decorated liquid metal(LM)inks are proposed with carbonaceous gallium–indium *** the assistance of biopolymers,the sodium alginate-encapsulated LM droplets contain high carboxyl groups which non-covalently crosslink with silk sericin-mediated MWCNTs.E-textile can be prepared subsequently via printing technique and natural waterproof triboelectric coating,enabling good flexibility,hydrophilicity,breathability,wearability,biocompatibility,conductivity,stability,and excellent versatility,without any artificial *** obtained e-textile can be used in various applications with designable patterns and ***-sensing applications of recognizing complex human motions,breathing,phonation,and pressure distribution are demonstrated with repeatable and reliable ***-powered and energy-harvesting capabilities are also presented by driving electronic devices and lighting *** proof of concept,this work provides new opportunities in a scalable and sustainable way to develop novel wearable electronics and smart clothing for future commercial applications.

关键词： Biocompatible Conductive ink Biopolymer E-textile Carbonaceous liquid metal

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Study on the mechanism and law of temperature,humidity and moisture content on the mechanical properties of molded fiber products

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Journal of Bioresources and Bioproducts 2024年第3期9卷 351-368页

作者： zhiqiang fu Tong Zhao Hu Wang Jingyi Wei Haozhe Liu Liying Duan yan Wang Ruixiang yan School of Light Industry Science and Engineering Tianjin University of Science and TechnologyTianjin 300457China Department of Transportation and Vehicle Engineering Tangshan UniversityTangshan 063000HebeiChina College of Mechanical Engineering Tianjin University of Science and TechnologyTianjin 300457China

The change of temperature, humidity and moisture content (MC) will lead to the change of mechanical properties of molded fiber products (MFP). However, it is difficult to decouple the effects of temperature, humidity and MC on the mechanical properties of MFP, and predict the mechanical properties of MFP during the use. In this study, the laws and mechanism of mechanical properties of MFP with ambient temperature, humidity and MC were studied. The results showed that the direct effect of temperature (20−70 °C) on mechanical properties of MFP was insignificant, and the mechanical properties of MFP were mainly changed by MC. The MC was related to ambient temperature and humidity, and the relationship between the three could be described by the modified Guggenheim-Anderson-de Boer (GAB) model (20−70 °C and 30 %–90 % relative humidity). With the increase of MC, the elastic modulus and fracture strain was increased and decreased linearly, the yield strength and failure strength were presented GaussAmp laws, and the failure strain was presented asymptotic regressed distribution law. Two fracture modes of MFP, brittle fracture and ductile fracture, were revealed by the scanning electron microscopy of the mesoscopic fiber structure of sugarcane bagasse molded fiber products. The mathematical models and the changes of fiber structure were verified by wheat straw molded fiber products and waste paper molded fiber products. This study was contributed to understand the effects and mechanism of the change of temperature, humidity and MC on the mechanical properties of MFP.

关键词： Temperature Relative humidity Moisture content Molded fiber products Mechanical properties

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Strain engineering of Pt-based electrocatalysts for oxygen reaction reduction

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Frontiers in Energy 2024年第2期18卷 241-262页

作者： Zeyu WANG yanru LIU Shun CHEN Yun ZHENG Xiaogang fu yan ZHANG Wanglei WANG State Key Laboratory of Solidification Processing Atomic Control and Catalysis Engineering LaboratorySchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China State Key Laboratory of Oral and Maxillofacial Reconstruction and Regeneration National Clinical Research Center for Oral DiseasesShaanxi Key Laboratory of StomatologyDepartment of Dental MaterialsSchool of StomatologyThe Fourth Military Medical UniversityXi’an 710032China Institute of New Energy Materials and Engineering School of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China Key Laboratory of Marine Chemistry Theory and Technology(Ministry of Education) College of Chemistry and Chemical EngineeringOcean University of ChinaQingdao 266100China

Proton exchange membrane fuel cells(PEMFCs)are playing irreplaceable roles in the construction of the future sustainable energy ***,the insufficient performance of platinum(Pt)-based electrocatalysts for oxygen reduction reaction(ORR)hinders the overall efficiency of *** the surface strain of catalysts is considered an effective way to tune their electronic structures and therefore optimize catalytic *** this paper,insights into strain engineering for improving Pt-based catalysts toward ORR are elaborated in ***,recent advances in understanding the strain effects on ORR catalysts are comprehensively ***,strain engineering methodologies for adjusting Ptbased catalysts are comprehensively ***,further information on the various challenges and potential prospects for strain modulation of Pt-based catalysts is provided.

关键词： strain engineering Pt-based catalysts oxygen reduction reaction(ORR) catalytic performance proton exchange membrane fuel cells(PEMFCs)

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Multi-physical fields distribution in billet during helical electromagnetic stirring:A numerical simulation research

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China Foundry 2024年第1期21卷 51-59页

作者： Dong Pan Qing-tao Guo Kai-lun Zhang fu-zhi Yu Yu-ying Li Yu-bao Xiao State Key Laboratory of Metal Materials for Marine Equipment and Application Anshan 114009LiaoningChina Ansteel Beijing Research Institute Co. Ltd.Beijing 102200China

Electromagnetic stirring is one of the widely applied techniques to modify the quality of casting *** from conventional rotate stirring,the helical stirring is more professional in assisting multi-dimensional flow of molten metal and eliminating solidification *** this study,the single-winding helical stirring(SWHS)was introduced,offering advantages such as smaller volume and lower electromagnetic shielding compared to traditional helical stirring *** a comprehensive numerical simulation,the stirring parameters of SWHS were adjusted to yoke inclination angle of 43°and frequency of 12 *** higher electromagnetic force and flow velocity in drawing direction,as well as the lower temperature gradient induced by the SWHS,are positive factors for homogeneous solidification of *** experimental results on Al-8%Si alloy and 0.4%C-1.1%Mn steel demonstrate that compared to rotate stirring,the SWHS process can induce better billet quality and is more effective in accelerating the equiaxed expansion and reducing element *** SWHS process can enhance the equiaxed ratio of the billet by 58.3%and reduce segregation degree of carbon element by 10.97%.Consequently,SWHS holds great promise as a potential approach for improving the quality of continuous casting billets.

关键词： billet electromagnetic stirring helical solidification element segregation numerical simulation

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